1990 Silverado - AC System Help

[ZombieK5]

Everyone. The AC System in my "new to me" '90 Silverado does not function. It still has the ORIGINAL R-12 compressor and related parts.

I NEED to fix the AC and realize it will have to be a R-134 system. Getting the compressor and related components is easy enough but I am finding that the options include the Orifice tube located either in the evaporator OR condenser. This is important because if the EXISTING system has the tube in the evaporator then I need to rip out the under dash box.

Any help with the options I need?

 

[toddball]

The orfice tube is at the high side port connection. Easy to swap, r134a works fine with the stock setup. Just pull a vacuum on the system, if it holds you can just add refrigerant and it should work with out changing the compressor, condensor or evaporator.

 

[ZombieK5]

The orfice tube is at the high side port connection. Easy to swap, r134a works fine with the stock setup. Just pull a vacuum on the system, if it holds you can just add refrigerant and it should work with out changing the compressor, condensor or evaporator.

The condenser is missing....Need to put a new one in.

If the orfice tube is at the high side port connection why are the options for condenser/evaporator mentioned on RockAuto.

So, is the orifice tube location, as you mentioned between the connection of two hoses. My Explorer's orifice tube is accessed by disconnecting two hoses on the high side.

 

[Wes Harden]

No the tube will be in the engine compartment. On the high pressure where it connects to the evaporator. Undo that connection and see the tube is there. Also can a royal pain in the ass to get them out

 

[toddball]

Do you have rear ac? Otherwise, it should be right here in the bottom evaporator connection.

 

[CT-BLAZER]

R12 is a more efficient gas..... The AC system, pump, evaporator, condenser were all designed for the old gas ...
Yes, I have a supply...



Does any company make a complete retro fit kit to make a R134 system in your area?

Jones AC in East Hartford, CT used to be the go to people for retro AC systems.

 

[Chickntrk]

You can still buy R22 and use it in place of R12…same basic gas

 

[toddball]

I would like to add to this discussion, that I have performed a Pepsi challenge. R12 in a 1990 suburban and 1985 k5 r134a in Tucson summer heat idling right next to each other. Using a infrared thermometer. There really is no difference, just have the right orifice tube.

 

[Blue85]

Why would the orifice tube be at the condenser? It would have to be on the outlet and then you'd have to insulate the whole line from there to the evap because you'd be cooling the engine bay as much as the passenger compartment.

 

[ZombieK5]

R12 is a more efficient gas..... The AC system, pump, evaporator, condenser were all designed for the old gas ...
Yes, I have a supply...



Does any company make a complete retro fit kit to make a R134 system in your area?

Jones AC in East Hartford, CT used to be the go to people for retro AC systems.

From my understanding you only need to replace the compressor accumulator and orifice tube to complete the retrofit. Everything else is simply tubing or aluminum condensor/evaporator.

 

[toddball]

Since you are missing the condenser, a new one will work better with r134a, the design is different than the old tube style. But everything else if not broken can been reused.

New accumulator is good practice too, flush out all the lines, use new o rings and seals. Pag oil for r134, mineral oil for r12. A retro fit kit usually just has new fittings that you put on the ports.

 

[Wes Harden]

Need to flush the old remaining components. Especially since they have been open.

 

[ZombieK5]

Since you are missing the condenser, a new one will work better with r134a, the design is different than the old tube style. But everything else if not broken can been reused.

New accumulator is good practice too, flush out all the lines, use new o rings and seals. Pag oil for r134, mineral oil for r12. A retro fit kit usually just has new fittings that you put on the ports.

Pretty sure I am going to replace everything except the Evaporator. (New hoses and everything else). I will blow out the evaporator and try to flush it.